OPHTHALMIC PACKAGE AND DELIVERY DEVICE

Abstract: An ophthalmic package (1) is formed by injection molding, having a thick wall with a limited flexible area (22), which limits internal displacement of the walls of the package (1) when squeezed to thereby deliver a certain amount per squeeze. The package has an integrally molded dropper tip, as well as an integrally molded break-off or puncture diaphragm within the tip. At the end of the package opposite the dropper tip is a bottom closure cap (3) which may be snapped into the package. The closure cap (3) includes a "displacement" member of a certain size to extend into the interior of the package (1) thereby taking up space and in so doing reducing the internal volumetric capacity of the package (1). The package (1) may be shaped to facilitate easy gripping and to prevent rolling.

Description: ΉTLE OF THE INVENTION OPHTHALMIC PACKAGE AND DELIVERY DEVICE TECHNICAL FIELD This invention relates to a liquid dispensing device especially useful in the dispensing of ophthalmic drugs which typically need to be dispensed in drop form. BACKGROUND OF THE INVENTION The present invention pertains to the art of liquid dispensers, and, more particularly, to a dispensing device for accurately dispensing small droplets of liquid. The invention is particularly applicable for use as an eyedropper and will be described with particular reference thereto although it will be appreciated that the invention has other and broader applications. Medicant drop dispensers of the type to which the present invention pertains are available in various sizes and shapes for the numerous medicines and solutions which are available for the care and comfort of the human eye. Heretofore, such dispensers have basically comprised a relatively small compressible plastic container or vial provided with a dispensing nozzle and cap. One problem associated with conventional eyedroppers is the difficulty in accurately controlling the amount of medicine dispensed, i.e., the number of drops dispensed. Most conventional eyedropper dispensers utilize one of two or a combination of these methods to achieve single drop control. One method uses a highly compliant plastic bottle which the user squeezes to dispense a drop. The extensive deflection of the bottle creates an significant internal air pressure within the vial which expels the liquid through the tip or dispensing nozzle. In order to prevent a continuous stream of liquid medicant from being expelled, and to create single drops, these designs incorporate a flow restriction at the inlet of the tip or nozzle. Unfortunately, this flow restriction does not limit the number of drops expelled during a single squeeze, but merely limits the liquid medicant flow rate favoring the formation of individual drops releasing from the dropper tip rather than a continuous stream. It should be obvious that this flow restriction, if truly effective in preventing a stream of liquid, will also make the dispensing of drops more difficult, especially for older patients as well as those with physical disabilities. Also, the creation of a very small molded orifice, frequently as small as .005" (.13 mm) in diameter creates manufacturing difficulties. In addition, the small orifice can be prone to clogging from particles of contamination sometimes drawn back into the bottle during usage or ° dried residue from the medicant formulation itself. Another method often used is to manufacture a bottle with relatively rigid (relatively non-compliant) walls. With this configuration, the force to deflect or squeeze the bottle is relatively high compared to the compliant bottle of the previous paragraph. Because of this increased 5 force necessary to deflect the plastic walls of the bottle, the user will tend to limit the squeezing action due to the difficulty encountered in the movement. However, increased force on the bottle will easily create a stream of liquid medicant to be expelled rather than a drop. Another disadvantage of this design is that it is frequently difficult to dispense 0 even a single drop, especially for older patients as well as those with physical disabilities. SUMMARY OF THE INVENTION The present invention contemplates a new and improved 5 dispenser device for dispensing droplets of liquid which overcomes all the above-referred to difficulties and provides a liquid medicant dispenser which accurately dispenses droplets of liquid medicant at desired locations without waste. In accordance with the present invention there is provided an improved drop dispenser for use with a closed compressible container, which dispenser is comprised of a tubular or ovoid dispenser member having walls relatively rigid and thick plastic. There is however incorporated into this bottle, a relatively small "target" area which is much more compliant than the remainder of the bottle. In the preferred embodiment of this invention, this target area consists of a combination of longitudinal pleats and thinner wall sections which make the target compliant and easy to push only for small displacements. After the small displacement, the squeezing force becomes very high. This small displacement of the target area is just sufficient to easily dispense a single drop. The user must release pressure on the bottle, allowing the plastic in the target area to return to its non-displaced position before pushing to dispense the next single drop. Although the preferred embodiment uses longitudinal pleat, other geometric variations to achieve the same means are also part of this invention. Other methods for creating the target area are: Thinner walls alone, pleats alone, bellows of any configuration, insertion of a lower flexural modulus (more compliant) material by separate molding or welding in place. Another advantage of this invention is that the relatively thick walls existing everywhere except in the small target area make this bottle much more resistant to water vapor or oxygen permeation which provides longer shelf life for the liquid medicant. Another advantage is that this lower permeation allows the usage of a larger size, easy to handle bottle even for low fill volumes of liquid medicant. Another feature of this invention is that the target area provides a convenient visible liquid level indicator for the patient. Another feature of this invention utilizes bottom plug of different lengths to allow various fill levels in the same bottle without creating excessive empty (air) space in the vial. This is important with certain sensitive formulations. Another feature of this invention is that the patient can use the bottom plug as an alternative dispensing button to the target area, with the same single-drop dispensing advantages. It will also be appreciated that both the bottom and the cap can be hermetically sealed further insuring the stability and integrity of the contents. The cap can also strive as a "seal-break cap." The nozzle can be formed with a barrier membrane across the opening. The inside of the cap fitting over this nozzle can be fitted with a suitably sized and shaped piercing point. The cap can be designed so that an initial half-turn of the cap punctures the nozzle barrier. Alternatively, the cap and bottle may be so designed so that the cap is pushed onto a break-off seal external to, but molded integrally with the nozzle. Upon initially unscrewing the cap in the normal (counter-clockwise) manner, the cap first severs the seal, allowing drops to be later dispensed after full removal of the cap. The cap or bottle can also be fitted with external tabs, wings, flanges, or other molded features which serve as a tamper-evidence device. Preferably the thin dispensing area is formed simultaneously when the dispenser is molded, using suitable injection molding techniques. Current ophthalmic packages utilize either injection blow molding, extrusion blow molding, or extrusion blow molding with in- place filling, often called blow-fill-seal. With all of these blow molding processes, there is only limited control over the final molded geometry and wall thickness of the part. The disadvantages lie in the fact that it is difficult to mix different geometries and wall sections in the same part to custom design for desired performance and dispensing characteristics. However, it is possible and should be part of the invention. With injection molding there is complete control over geometry and wall thickness. This subject invention is able to combine thick- walls for very low overall water vapor transmission, selective flexibility for easy dispensing, side or bottom dispensing, limited displacement for single drop control, single outside image for all fill volumes, and desirable hermetic seals, easy patient opening, and integral tamper evidence. OBJECTS A principal object of the invention is the provision of a new and improved device for dispensing drops of liquid medicant which is simple and economical in construction and easy to use, and which affords more accurate control over the amount of liquid medicant dispensed therefrom. Other objects include: (1) Low cost high speed production; (2) One size outer image for all liquid fill levels; (3) Low permeation weight loss = longer shelf life; (4) Easy one drop dispensing; (5) Easy grip roll resistant bottle; (6) Easy open tamper evident vial; (7) Hermetically sealed; (8) Side or bottom dispensing; (9) Single drop dispensing; (10) Suitable for in-line molding/sterilization/filling/sealing/ labeling. Another key object is to utilize injection molding technology. Injection molding permits the formation of a separate thin- walled dispensing area having greater flexibility then one surrounding relatively rigid and thicks wall of the container. DRAWINGS The invention may take physical form in certain parts and arrangement of parts, a preferred emdodiment of which will be described in detail in this specification and illustrated in the accompanying drawings wherein: Figure 1 is a diagrammatic view of the ophthalmic container including bottom and caps. Figure 2 is a view of a similiar opthalmic container, but illustrating a variant bottom plug, and omitting the cap. Figure 3 is a cross-section of either container of Figures 1 or 2, taken along line A-A of Figure 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings wherein the showing is for the purpose of illustrating a preferred embodiment of the invention only and not for the purpose of limiting the same, FIGS. 1 and 2 shows an enlarged partial assembly of a liquid drop dispenser according to the present invention. The device is comprised of a compressible plastic container or vial 1, a cap member 2, and a bottom closure 3. Container or vial 1 contains a supply of liquid 10, medicant for instance, to be dispensed in droplet form. The container 1 has an integral reduced diameter open neck portion 12 provided with external helical screw threads 14 over the uppermost part of the neck end portion as shown in FIG. 1. The screw threads 14 are adapted to matingly engage internal threads 16 on cap member 2 to thereby attach the latter in place on container 1 in liquid-tight relation thereto. Cap member 2 comprises a generally cylindrical mounting or base portion 20 and a inside nozzle end portion point 21 projecting endwise therefrom. The bottom closure 3 is shaped so that it can allow different fill levels as shown. Container vial 1 is generally a relatively rigid, thick walled plastic suitable for injection molding such a polyethylene, polypropylene, or the like. According to the preferred embodiment shown cross-section in Figure 3, there is a "target area" 22 located in the side wall of the container. This target area is positioned in larger radiused section of the oval shaped cross-section. This target area could also be located in any flat, concave, convex or other area of the container. Through the use of any combination of geometric variations in the wall section, a small area of increased flexibility is created in the otherwise rigid container. In the preferred embodiment illustrated in figure 3, the target area is created through a combination of thinner wall sections and straight pleats which are easily injection molded. By whatever geometric means created, this more flexible target area allows the user to easily depress the container, but only through a very limited displacement. After this limited displacement, sufficient to expel a single drop, the force to create further displacement increases rapidly, making the expulsion of a second drop difficult without full release and reapplication of the squeezing pressure. Although this preferred embodiment provides for the dispensing of a single eye drop, this just described mechanical action can be adjusted to allow for the dispensing of any desired dosage from a single drop (approximately 30 to 50 microliters), to multiple drops, or even larger non-droplet dosages as high as 25 milliliters (cc.) by adjusting the container size and geometry.

Claims: WHAT IS CLAIMED IS: 1. An opthalmic plastic package and dispenser which has a stiff thick wall and a limited flexible area, which limits the displacement volume when squeezed. 2. The package of Claim 1 which has a separate cap acting as a seal-break or seal puncture device. 3. The package of Claim 1 having an integral molded dropper tip and a bottom cap which can optimally serve as a displacement member to reduce internal volume. 4. The package of Claim 1 having a shape which Umits rolling.

Inventors: LIFSHEY ARTHUR L, LIFSHEY, ARTHUR, L.
Applicants: LIFSHEY ARTHUR L, MERCK & CO INC, LIFSHEY, ARTHUR, L., MERCK & CO., INC.
Application year: 1994
Main classification: B65D47
IPC codes: A61F9, A61J1, B65D47, B65D51, B65D83